The human herpesvirus 8 homolog of Epstein-Barr virus SM protein (KS-SM) is a posttranscriptional activator of gene expression

J Virol. 2000 Jan;74(2):1038-44. doi: 10.1128/jvi.74.2.1038-1044.2000.

Abstract

Homologs of the Epstein-Barr virus (EBV) SM protein exist in several human and nonhuman herpesviruses. Structure and function differ significantly among these proteins. We have cloned and characterized the human herpesvirus 8 (HHV8) gene, KS-SM, which is homologous to the EBV SM and herpes simplex virus ICP27 genes, from an HHV8-infected primary effusion lymphoma. KS-SM is shown to be a posttranscriptional activator of gene expression in cotransfection studies. KS-SM activated gene expression in a gene-specific, promoter-independent manner. In particular, KS-SM enhanced the expression of KDR/flk-1, a receptor for vascular endothelial growth factor (VEGF), in cotransfection studies. Since expression of KDR/flk-1 is increased in Kaposi's sarcoma and HHV8-infected cell cultures and VEGF enhances the proliferation of HHV8-infected cells, KS-SM may play a pathogenic role in Kaposi's sarcoma.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Cloning, Molecular
  • Gene Expression
  • Gene Expression Regulation, Viral*
  • Genes, Viral
  • Herpesvirus 4, Human / genetics*
  • Herpesvirus 8, Human / genetics*
  • Humans
  • Introns
  • Molecular Sequence Data
  • Phosphoproteins / genetics*
  • RNA Processing, Post-Transcriptional
  • Sequence Homology, Amino Acid
  • Trans-Activators / genetics*
  • Transfection
  • Viral Proteins / genetics*

Substances

  • KS-SM protein, Human herpesvirus 8
  • Phosphoproteins
  • SM protein, Human herpesvirus 4
  • Trans-Activators
  • Viral Proteins